Rapid cool iron and related iron improvements

ABSTRACT

A rapid cool iron has a body and a low specific heat sole plate having an element bonded to or formed upon a top surface, said body and said sole plate being separated by an air gap to allow for the free flow of air over said top surface of said sole plate. Also taught is a fan to more rapidly cool the sole plate through forced convection. Also taught is a controller that is configured to only apply power when the rapid cool iron is in a horizontal orientation. Also taught is a steam generator which may be independent from or integrated with the sole plate, an external water reservoir/stand which includes a water filter, an ergonomically designed tilt handle with integrated controls and a grip sensor, and a forward facing light to illuminate the material being ironed.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] This invention relates to a rapid cool iron that may achieve operating temperatures very quickly, and then rapidly cool to a “safe touch” temperature after use. Further, this invention includes several related innovations that improve the overall design, convenience, and functionality of the household iron.

[0003] 2. Acknowledgement of Prior Art

[0004] Irons have been around for many, many years. In fact the original “irons” were just that—a conveniently shaped piece of iron that was designed to hold as much heat as possible for pressing clothes.

[0005] Modern irons may look similar to their predecessors, but they have been substantially improved. Initially, the advent of an electric element that allowed the heat source to be placed inside the iron added a tremendous amount of convenience. This has been followed by a long list of features including steam, temperature control, visible water reservoirs, and non-stick bottoms.

[0006] While irons have come a long way, there are still some fundamental problems that need to be resolved. There has always been an uneasy feeling about the safety or irons because they retain so much heat. The fear of the hot surface falling on an unsuspecting toddler or pet is a prevalent concern.

[0007] From an ergonomic standpoint, it is unfortunate that current iron designs incorporate a fixed handle, dictating that the user's hand will always remain parallel to the ironing board surface. This is simply not a valid assumption since users come in many shapes and sizes, and users may sit or stand while ironing. Simple body mechanics show that the wrist is forced to assume some very awkward positions to accommodate the fixed handle.

[0008] Most irons today are inefficient, consuming more than 1000 watts of power over extended periods of time. While this may be acceptable when ironing, the power is not fully utilized during warm-up or idle periods. Some irons do incorporate an auto shut-off feature to save power, but it should be noted that the element will remain hot for quite some time due to it's relatively high specific heat.

[0009] One of the most inconvenient aspects of today's irons is the way in which the water is added to the reservoir. Instructions from the manufacture recommend that the water should be filters, distilled, or otherwise conditioned before use. Then it must be poured through a relatively small capacity hole in the iron. In many cases the user will skip the first step and fill the iron directly from a tap. this actually presents a potential safety hazard, since the iron may still be plugged in during this process, and it may ultimately result in calcium build-up and corrosion within the steam generating system.

[0010] Several of these factors are linked together. For example the fixed handle is due in part to the fact that it also serves as a funnel when filling the water reservoir. Also, the safety concern over excess heat is linked to convenience since the iron must be left “on” during short idle periods to ensure that it is still hot when the user resumes ironing.

[0011] There have been several attempts to address and resolve these widely recognized problems as indicated by the proliferation of recent prior art in this field including U.S. Pat. No. 6,243,976 issued June 2001 to Beverly et al (assigned to Hamilton Beach/Procter Silex Inc.), U.S. Pat. No. 6,176,026 issued January 2001 to Leung (assigned to Simatelex Manufacturing Company), U.S. Pat. No. 6,104,009 issued August 2000 to Man (assigned to HP Intellectual Corporation), U.S. Pat. No. 6,079,133 issued June 2000 to Nethen (assigned to Philips Corporation, NY), U.S. Pat. No. 6,024,903 issued February 2000 to Naft, et al (assigned to HP Intellectual Corp.), U.S. Pat. No. 5,922,228 issued July 1999 to Hall, et al (assigned to HP Intellectual Corp.), U.S. Pat. No. 5,883,358 issued March 1999 to Brandolini, et al (assigned to SEB, S.A., France), U.S. Pat. No. 5,852,270 issued December 1998 to Mak, et al (assigned to Windmere Corporation), and U.S. Pat. No. 5,535,534 issued July 1996 to Li.

[0012] Several of these patents deal with the safety issue including U.S. Pat. No. 6,104,009 to Man, U.S. Pat. No. 5,883,358 to Brandolini, U.S. Pat. No. 5,852,279 to Mak, and U.S. Pat. No. 5,535,534 to Li.

[0013] U.S. Pat. No. 6,104,009 to Man teaches a series of timers connected to sensors mounted in the handle and internally to turn the iron off after a pre-determined amount of time depending on it's vertical or horizontal orientation. In a similar manner, U.S. Pat. No. 5,852,279 to Mak teaches a timer with sensors in the handle and “heel” of the iron to turn off the iron after a pre-determined amount of time depending on its vertical or horizontal orientation. U.S. Pat. No. 5,535,534 to Li teaches a protective shield which will automatically move into place to prevent accidental contact with the hot edge of the heating element.

[0014] In contrast to the above, U.S. Pat. No. 5,883,358 to Brandolini teaches a thin sole plate that is covered on the top side by a stiffening and thermally insulating structure which is permeable to steam. The low specific heat sole plate heats rapidly, and may therefore be turned off between ironing activities, even while the iron is in the horizontal position, by sensing that the user has released the grip on the iron's handle. Only the exposed or bottom surface of the tin sole plate is cooled through natural convention while in the vertical position.

[0015] A few of these patents deal with ergonomic and water fill issues including U.S. Pat. No. 6,243,976 to Beverly, et al, U.S. Pat. No. 6,176,026 to Leung, and U.S. Pat. No. 6,024,903 to Naft. U.S. Pat. No. 6,243,976 to Beverly, et al, teaches a fill port assembly that may be covered to prevent the ingress of dirt particles. U.S. Pat. No. 6,176,026 to Leung teaches a water reservoir and stand that may be used to automatically re-fill the iron's internal reservoir, however the user must first fill a bottle with prepared water, and then he bottle must be inverted and then placed on the stand. U.S. Pat. No. 6,024,903 teaches a process for manufacturing a comfort grip handle for an iron.

[0016] The remaining patents deal with performance and material issues including U.S. Pat. No. 6,079,133 to Nethen and U.S. Pat. No. 5,922,228 to Hall, et al. U.S. Pat. No. 6,079,133 to Nethen teaches a power control circuit that adapts the power applied to the sole plate heating element in anticipation of steam generating requirements to prevent a cooling of the sole plate during the initial stages of steam production. U.S. Pat. No. 5,922,228 to Hall teaches a vertical space between various iron components to contribute to improved air circulation and to prevent the melting of plastic parts.

SUMMARY OF THE INVENTION

[0017] In contrast to the above, the current invention disclosed means to address the three fundamental areas where a substantial improvement in iron design may be achieved.

[0018] First, the current invention disclosed a very low specific heat sole plate which is exposed on all sides and can change temperature very rapidly. This fundamental property allows the iron to achieve the underlying design objective—improved safety through rapid cooling. It also allows the iron to be heated very rapidly, precluding the usual warm-up and idle periods and therefore saving energy. This characteristic allows the iron to be controlled with an “on when horizontal/off when vertical” paradigm. The modular nature of this type of element means that steam production may be integrated or may be handled as a separate function.

[0019] One potential drawback of a low specific heat element is that it is very light. this may be addressed by adding weight to the iron to provide the necessary downward pressure and comfortable “feel”. It should be noted that the center of gravity and balance characteristics now become part of the design equation since the weight(s) can be added on a very deliberate basis, adding to the overall ergonomics of the iron.

[0020] Second, the current invention disclosed an external water reservoir that is much easier to fill and inherently safer since it is never connected to a power supply. while some inventors have already taken steps in this direction, the present inventors have developed the concept further to (1) incorporate a water filter and (2) use the reservoir as a stand to improve the stability of the iron at rest. The built-in filter is an added convenience for the user and it will extend the life of the iron by reducing the internal build-up of impurities.

[0021] The reservoir may also be used as a heat sink to improve the flow of heat away from the sole and induce a more rapid cooling rate. This could be enhanced through the use of additional technologies such as thermoelectric heat pumps and/or phase change heat pipes that can remove heat even more rapidly from the exposed ironing plate.

[0022] Third, the current invention discloses a well designed, comfortable, tilting handle that will fundamentally change the ironing experience. It should be noted that the handle is now free to move since it is no longer required as a filling point for the water reservoir. The real focus in designing the handle may now be what it should be—ergonomics—since this is the “high touch” part of the iron. Newer soft touch materials can be used to enhance comfort and visual distinctiveness. Controls can be placed where they are most convenient—not at the end of the handle where they are difficult to reach for short thumbs, but under the handle where they can be “squeezed”. Further, a light may be added to the end of the tilt handle, or at the forward part of the iron base, to improve workspace illumination for those who iron while watching TV, or in a poorly lit area.

[0023] Accordingly, this invention relates to a rapid cool iron and related iron improvements. The invention comprises (a) a very low specific heat sole plate that is exposed on all sides and may be heated and cooled rapidly, (b) a control circuit that turns the iron on when horizontal and off when vertical, (c) a forced convection fan that may more rapidly cool the sole plate when the iron is off, (d) a steam generator which may be independent of or integrated with the sole plate, (e) an external water reservoir that incorporates a water filter at the filling end and may also act as an iron stand and an auxiliary heat sink for the further removal of heat from the sole plate, (f) a comfortable tilt handle that incorporates easily accessed controls, and (g) a forward facing light to illuminate the material being ironed.

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Embodiments of the invention are described by way of example with reference to the drawings in which;

[0025]FIG. 1 is a side view of the rapid cool iron and related improvements,

[0026]FIG. 2 is a side view of the rapid cool iron in the base unit/reservoir,

[0027]FIG. 3 is a bottom view of the rapid cool iron sole plate,

[0028]FIG. 4 is a sectional view of a rapid cool iron sole plate with an independent steam generator, and

[0029]FIG. 5 is a sectional view of a rapid cool iron sole plate with an integrated steam generator.

[0030]FIG. 1 is a side view of the rapid cool iron and related improvements. Composite element/sole plate 10 is separated from the bottom of iron base 12 by air gap 14. Composite element/sole plate 10 may be of thin, low specific heat material with a resistive element bonded to or constructed upon the top surface as available from several suppliers such as Minco and Elmwood Sensors.

[0031] Composite element/sole plate 10 is heated by applying power, and may be cooled by removing power while simultaneously blowing air through air gap 14. This forced convection is driven by fan 16 which is located in the mid section of iron base 12 and directs air downwards such that it impinges upon and then flows across the top surface of composite element/sole plate 10. Fan 16 may be left on at all times, or alternatively at all times that the temperature of composite element sole plate 10 is above a “safe touch” temperature of, say, 45 C. Further, fan 16 may be turned on only when the iron is in a vertical position in order to conserve energy.

[0032] The temperature of composite element/sole plate 10 is controlled by temperature control 18. It should be noted that the accuracy of temperature control becomes more important with a rapid cool iron since composite element/sole plate 10 has a lower specific heat and therefore less thermal mass than with other irons. The temperature of composite element/sole plate 10 will rise very rapidly when power is applied, and temperature control is important to prevent a dangerous overheating situation. The response time and overshoot characteristics of temperature control 18 must be sufficient to manage the low specific heat characteristics of composite element/sole plate 10.

[0033] Water to produce steam enters the rapid cool iron through water port 22 which is located at the base of the iron, when the iron is in the vertical orientation, so that it may mate with the reservoir base (reference FIG. 2) when at rest. This location of water port 22 frees tilt handle 20 from all encumbering connections, thus allowing it to tilt for convenience.

[0034] Tilt handle 20 may be ergonomically designed with steam/spray controls 24 located within easy reach on the under side of the handle, but configured such that they are not easily activated when the iron is picked up. Other features such as palm rest 26 may be added to tilt handle 20 for additional comfort and convenience.

[0035] Main power to rapid cool iron 1 is controlled by on/off switch 28. Once on/off switch 28 is placed in the “on” position, control is passed to internal mercury switch 30. Mercury switch 30 is positioned and connected such that composite element/sole plate 10 only receives power when rapid cool iron 1 is in the horizontal position, and does not receive power while in the vertical position. Composite element/sole plate 10 is of such low specific heat that is reaches operating temperature very quickly (typically 200 C. in 10-12 seconds), thus precluding the requirement for any “warm up” period.

[0036] Safety may be further enhanced by mounting a “grip” sensor on tilt handle 20 in conjunction with steam/spray controls 24. In this case the “grip” sensor must be activated by the user AND (logical AND) internal mercury switch 30 must sense that the iron is in the horizontal position before power is applied to composite element/sole plate 10. This will serve to automatically turn off the iron should it be left unattended in the horizontal position and/or fall into a horizontal position.

[0037] Internal mercury switch 30 may also be used to control power to light 32, illuminating light 32 when the iron is in the operating or horizontal position.

[0038] Internal mercury switch 30 may also be used to control power to fan 16 such that fan 16 operates only when the rapid cool iron 1 is in the vertical or non-operating position. Alternatively fan 16 may be safely left on at all times in order to reduce the complexity of the controls and internal wiring, however this will result in wasted energy since heat from composite element/sole plate 10 will be needlessly dissipated during the ironing process.

[0039]FIG. 2 is a side view of the rapid cool iron in the base unit/reservoir. Base unit/reservoir 40 has two primary functions: (1) to ensure that the iron is steady while at rest and (2) to provide a ready supply of water which can then be used by the iron to generate steam. The first function is quite evident with the top of base unit/reservoir 40 being designed to accept the back of rapid cool iron 1 and steadily retain it in a vertical position. (Rapid cool iron 1 may be further designed to stand vertically without the base, albeit in a less stable manner.) The second function is initiated by rapid cool iron 1 which supplies a pressure to the base unit/reservoir, when it is resting thereupon, through pressure line 46. This pressure serves to “push” a supply of water back up into internal reservoir 42 through water line 48.

[0040] Internal steam generator 44 may be used to generate steam. Further, internal steam generator 44 may be independent of or integrated with composite element/sole plate 10. An independent steam generator 44 will allow composite element/sole plate 10 to be constructed with a very low specific heat characteristic. Also, the separation of ironing and steam generating elements has the added benefit of allowing some versions of rapid cool iron 1 to generate steam in the vertical position while maintaining a cool composite element/sole plate 10. This would be an extremely useful and safe feature for some ironing requirements such as removing wrinkles from drapes.

[0041] Internal steam generator 44 may also use heat to generate a regulated pressure which enters base unit/reservoir 40 through pressure line 46 such that water in base unit/reservoir 40 is pushed back into internal reservoir 42 through water line 48. The required pressure is quite safe since the water only needs to travel a vertical distance of approximately ½ the length of the iron. Pressure line 46 and water line 48 are both automatically connected to base unit/reservoir 40 when the rapid cool iron 1 is placed into base unit/reservoir 40. Upon disconnection, pressure and water are safety maintained in both the base unit/reservoir 40 and rapid cool iron 1 by self sealing auto-load connects 50.

[0042] The level of water remaining in the base unit/reservoir 40 can be easily determined by inspecting water level window 52. Internal reservoir 42 is sized to accommodate most ironing requirements that might occur between successive rest points—i.e. between each time the iron is placed in base unit/reservoir 40. It will be obvious to the user when internal reservoir 42 runs out of water since the iron will no longer generate steam. The simple and obvious solution will be to place rapid cool iron 1 back into base unit/reservoir 40 for a brief period of time.

[0043] Base unit/reservoir 40 can be filled through built-In funnel 54. During this process, the water runs through filter 56 which may be configured to remove impurities and/or other factors contributing to water hardness. Water fill gasket 58 serves to seal the entrance to built-In funnel 54 such that sufficient pressure may be developed within base unit/reservoir 40 to drive water up into internal reservoir 42. Water fill gasket 58 is conveniently located at the back of tilt handle 20.

[0044]FIG. 3 is a bottom view of the rapid cool iron sole plate showing the location of section A-A. Steam holes 70 are distributed around composite element/sole plate 10 to allow for the even escape of steam for ironing purposes.

[0045]FIG. 4 is a sectional view (A-A) of a rapid cool iron sole plate with an independent steam generator. Steam Holes 70 may be approximately ⅛″ in diameter and may be created with a slight protrusion on the top of composite element/sole plate 10. Gasket seals 82 are positioned around each protrusion to form a seal between iron base 12 and composite element/sole plate 10. The thickness of gasket seals 82 is designed to be slightly larger than the height of air gap 14 in order to provide a slight compression when the unit is assembled. Steam holes 70 line up with their counterparts in the iron base 12 to allow for the free flow of steam there through.

[0046] Fan 16 is positioned to create a downward air flow 84 which then impinges upon and disperses over the top of composite element/sole plate 10, and out through air gap 14. This more rapidly cools composite element/sole plate 10 through forced convection.

[0047]FIG. 5 is a sectional view of a paid cool iron sole plate with an integrated steam generator. In this case steam barrier 94 may be vulcanized or otherwise fastened to the top of composite element/sole plate 10 with steam seal 96 around the perimeter of steam barrier 94 such that a steam chamber 98 is formed between the bottom of steam barrier 94 and the top of composite element/sole plate 10.

[0048] Water may enter steam chamber 98 through water port 90 which may be inserted into internal reservoir 42 (reference FIG. 2) and sealed against leaks by o-ring 92. Water then comes in contact with the electrically insulated top surface of composite element/sole plate 10 where the heat produced by composite element/sole plate 10 turns the water into steam. The pressurized steam then exists through steam holes 70. Steam barrier 94 may extend along the length of composite element/sole plate 10 such that it covers all of the steam holes 70 as depicted in FIG. 3. Steam holes 70 may be discrete holes, or they may formed by using a semi-permeable material for composite element/sole plate 10, at least in the area under steam barrier 94, to allow for the release of steam when under pressure.

[0049] The incremental latent heat required to vaporize the water may be generated by a single element bonded to or formed upon the top surface of composite element/sole plate 10 having a variable watt density such that the watt density is greater in the area under steam barrier 94. Alternatively, a first element may be bonded to or formed upon substantially all of the top surface of composite element/sole plate 10 to produce the heat required for the ironing process, and a second element may be bonded to or formed upon the top surface of the seam composite element/sole plate 10 only in the area covered by steam barrier 94 in order to produce the incremental latent heat only when required. Alternatively, a single element may be bonded to or formed upon substantially all of the top surface of composite element/sole plate 10 to produce the heat required for the ironing process, and a second element may be bonded to or formed upon a surface of steam barrier 94 to produce the incremental latent heat only when required. Note that in the latter two cases the energy required to produce the incremental latent heat may be selectively used at the time of or in anticipation of the steam requirement, and that the heat is localized in the correct area. Note also that this steam generation process operates independently from the temperature control required for composite element/sole plate 10. Steam barrier 94 may be constructed of thin, low specific heat, and highly thermally conductive material such as a stainless steel. This will allow steam barrier 94 to effectively dissipate heat from the top surface of composite element/sole plate 10, and this process may be aided by forced convection as fan 16 creates air flow 16 which will impinge directly on steam barrier 94 and then exit through air gap 14, i.e. the gap between composite element/sole plate 10 and iron base 12 (reference FIG. 4).

[0050] The conduction of heat between composite element/sole plate 10 and steam barrier 94 may be enhanced through the use of support/conduction pins 100. Note that the use of support/conduction pins 100 will also contribute to the overall rigidity of the combined composite element/sole plate 10 and steam barrier 94 assembly. 

We claim:
 1. A rapid cool iron comprising: a) a rapid cool iron body; b) a low specific heat sole plate having an element bonded to or formed upon a top surface; c) a means to mount said sole plate on a plane below the bottom surface of said rapid cool iron body; d) an air gap between said sole plate and said rapid cool iron body allowing the free flow of air between said sole plate and said rapid cool iron body.
 2. A rapid cool iron as claimed in claim 1 further comprising a fan that is positioned to direct air over the top surface of said sole plate and more rapidly cool said sole plate through forced convection.
 3. A rapid cool iron as claimed in claim 1 further comprising a control circuit that is in communication with a power source and is configured to apply power to said sole plate when said rapid cool iron is in a horizontal orientation, and to not apply power to said sole plate when said rapid cool iron is in a vertical orientation.
 4. A rapid cool iron as claimed in claim 1 further comprising a steam generator which may be independent from said sole plate.
 5. A rapid cool iron as claimed in claim 1 further comprising a steam generator which may be integrated with said sole plate, said steam generator being formed by placing a cap over a portion of said sole plate, said cap being in thermal communication with said sole plate and positioned and mounted such that air may flow freely over the exposed surface of said cap.
 6. A rapid cool iron as claimed in claim 1 further comprising a second element for the generation of steam, said second element being in communication with a power supply when steam is required or in anticipation thereof.
 7. A rapid cool iron as claimed in claim 1 further comprising an external water reservoir which may be filled through an integrated filter, said external water reservoir being located in a stand for said rapid cool iron, and said external water reservoir being in communication with a smaller reservoir internal to said iron when said rapid cool iron is placed in said stand.
 8. A rapid cool iron as claimed in claim 1 further comprising a tilt handle, said tilt handle being ergonomically designed and covered with a soft touch material, said tilt handle incorporating controls and sensors for said rapid cool iron, and said controls and sensors located for comfortable access.
 9. A rapid cool iron as claimed in claim 1 further comprising a safety sensor on a handle, said safety sensor positioned to sense the presence of a user's hand on said handle, and said safety sensor having a first connection to a power supply and a second connection to the internal components of said iron and configured such that said internal components may only be connected to said power supply said rapid cool iron is in use.
 10. A rapid cool iron as claimed in claim 1 further comprising a forward facing light, said light positioned to generally illuminate the material to be ironed by said rapid cool iron. 